An exhaust heat recovery apparatus includes a heat exchanger having a medium to be heated by a heat of an exhaust gas generated within an internal combustion engine. Such an exhaust heat recovery apparatus is known from, for example, JP-A-2009-30569. FIG. 8 hereof shows an exhaust heat recovery apparatus disclosed in JP-A-2009-30569.
As shown in FIG. 8, an exhaust heat recovery apparatus 100 has an inlet port portion 101 for introducing an exhaust gas, a first flow passage portion 102 extending from the inlet port portion 101, and a second flow passage portion 103 bypassing the first flow passage portion 103 above the first flow passage portion 102. The exhaust heat recovery apparatus 100 also includes a heat exchanger 104 disposed in the second flow passage portion 103 for providing heat exchange between an exhaust gas and a medium. The apparatus 100 further includes a valve shaft 105 disposed proximate a downstream end 102a of the first flow passage portion 102, and a valve 106 supported by the valve shaft 105.
The valve 106 includes a first valve body 107 supported by the valve shaft 105, and a second valve body 108 extending from a back side of the first valve body 107 toward a downstream end 103a of the second flow passage portion 103.
When a temperature of a medium flowing through the heat exchanger 104 is low, the downstream end 102a of the first flow passage portion 102 is closed by the first valve body 107. With the downstream end 102a closed by the first valve body 107, an exhaust gas is directed into the second flow passage portion 103 for heat exchange between the exhaust gas and the medium in the heat exchanger 104. The medium is heated due to the heat exchange. When the medium is sufficiently heated, the valve shaft 105 is rotated causing the second valve body 108 to close the downstream end 103a of the second flow passage portion 103. With the downstream end 103a closed by the second valve body 108, the heat exchange does not occur.
The valve 106 includes a guide portion 109 extending from a distal end portion of the second valve body 108 to the downstream end 103a of the second flow passage portion for guiding the second valve body 108 so as to precisely close the second flow passage portion 103. However, since the valve 106 includes this guide portion 109, a size of the valve 106 is undesirably large.